Coating apparatus



June 24, 1930. T. BIRKENMAIER 'COATING APPARATUS 4 Sheets- Sheet 1 Filed Aug. 1925 WEM III. l ll June 24, 1930. T. BIRKENMAIER COATING APPARATUS 4 Sheets-Sheet 2 Filed Aug. 1, 1925 42 f /fij m" 79 /i7 /9 F 3.9 .33 9/ 10/ war June 24, 1930. slRKENMAlER' 1,765,522

COATING APPARATUS Filed Aug. 1925 4 Sheets$heet 5 June 24,1930. v BIRKENMAIER 1,765,522

COATING APPARATUS Filed Aug. 1, 1925 4 Sheets-Sheet 4 Patented June 24, 1930 UNITED STATES PATENT OFFICE THEODORE BIRKENHAIER, OF ST. LOUIS, MISSOURI, ASSIGNOR 'IO W. N. IATTHE'WS CORPORATION, '1. LOUIS, MISSOURI, A CORPORATION 01 MISSOURI COATING APPARATUS Application filed August 1, 1925. Serial No. 47,893.

This invention relates to paint guns and with regard to certain more specific features to a liquid gun for preferably spraying lacquers and the like.

' 5 Among the several objects of the invention may be noted the provision 'of a lacquer or paint gun from which liquid drips cannot escape while the n is in operation, one which is operable without dripping in its upright and in various inverted ositions and one which has its nozzle and 0t er parts so constructed that derangements due to wear and tear are eliminated. Other ob- -jects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the features of construction, combinations of elements and arrangements of parts, which are exemplified in the description hereinafter in connection with the accompanying drawin s, and the scope of the application of whic will be indicated in the following claims.

In the accompanying drawings in which are illustrated two of various possible embodiments of the invention,

Fi 1 is a fgmt elevation of the assemb ed gun with parts broken away;

-Fig. 2 is a, longitudinal vertical section so of the assembled gun;

. Fig. 3 is a longitudinal enlarged. sectlon of the nozzle portions;

Fi on the line of Fi 2- and shows in dashed lines the genera sectional contour of the spray due to one adjustment;

Fig. 5 is a view similar to Fig. 4 showing another position for the spray conto'ur due to another adjustment;

placed upright; Fig. 7 1s a view similar to Fig. 6 showing the gun tilted forward;

Fig. 8 is a view similar to Fig. 6 showing the gun inverted;

4 is a lateral vertical section taken Fig. 6 'is a side elevation of the gun Fig. 14 is a vertical section of another 8.1-

ternate form of vent tube.

Like numerals indicate corresponding arts throughout the several views of the rawings.

Referring now more particularlyto Figs. 1 and 2 there is illustrated at 1 a gun assembly and at 3 a reservoir assembly. These are fastened together by the bored removable couplin ni ple 5, of the stand ard type and whic is tted to the reservoir assembly 3 in liquid tight fashion. The gun assembly may be removed from the reservoir assembly at will and a material or liquid line attached thereto. The present invention regards particularly however a portable reservoir as will now be The reservoir 3 comprises an inverted can or container 7 made of stout material. A stay 9 is riveted or otherwise made fast to the top of the container, preferably at the center thereof where a proper boss is provided. The stay 9 passes longitudinally;

of the container to ltSlOWGl end. A removable lid 11, provided with a gasket 13 in au annular groove, fits up against the lower end of the container and seals it. The lid is formed with an n ward de ression 15 and a bore centrally tereof. he bore is ada ted to loosely receive the lower end of sai stay 9 which is threaded within the crater deplression 15and receives a thumb nut- 17 t ereon. A concentric lip 19 is described.

formed on the lower surface of the depression and engages a gasket 21 set into a concentric groove of said nut 17 whereby leaka e past the nut is prevented. The three ed portion between the stay 9 and the nut 17 does not leak because it is of the taper type. The gasket 21 seats before the nut 17 becomes tight on the stay 9. All parts of the nut 17, including its wings, as well as the lower end of stay 9 are confined within the limits of the depression 15, whereby the reservoir assembly with its gun thereon may be set down on fiat suraces.

To seal the container, the lid 11 need merely be slipped over the stay bolt 9, the nut 17 applied and drawn up, whereupon said lid 11 is forced against the can 7 under reaction of the nut 17 advancing on the bolt 9.

Within the container 7 is provided a curved supply pipe 23 leading from the nip pie 5, (which nipple is located on one side of the stay 9) to the front side and the bottom of the container 7. This arrangement provides immersion for the intake end of the pipe 23 at all times, even though the gun and reservoir are tilted forward as shown in Fig. 7. In the Fig. 7 position all liquid may be abstracted from the'container by the tube 23. The heavy dashed line in Fig. 8 shows the liquid level possible when the gun is between the positions shown in Figs. 7 and 8 and it is obvious that even in such a position a great amount of the liquid may be removed. in the Fig. 8 position (an extreine condition) some liquid may be obtained in the pipe 23.

To obtain liquid from a closed vessel it is necessary to provide a vent therefor. It

will not do, here, to merely punch a hole in the top of the container as leakage will result upon tilting. To obviate this a vent pipe 25 is passed through a boss in the container top in liquid tight fashion. This pipe 25 leads from. within a short distance .of the bottom 11 at the rear side thereof,

through the top of the container and extends upwardly above said top to form an expansion chamber 27. On the top of the chamber 27 is screwed a vented cap 29.

It is obvious that upon filling the inverted container 7, no liquid need be poured into the pipe 25. When the container is sealed and turned over equal heads of liquid are established within the pipe 25 and without said pipe (Fig. 6). As liquid is withdrawn from the container the head in the pi e 25 decreases and air is drawn in throug the cap. Finally when said head is depleted air enters the container as needed through the ipe 25.

The pipe 25 is bent slightly toward the rear of the container 7 (Fig; 7) whereby the lower end thereof, whenthe device is tipped forward, leaves the surface of the liquid before the slope of the pipe is such that liquid can be carried out of the cap 29 by gravity.

gun, the tube 25 acts as a vent in all ositions of this device, including that of F 1g. 8.

The chamber 27 serves another purpose, namely as an expansion overflow chamber when pressure builds u in the container 7 due to heating of the liquid therein. Lacquers, and like liquids for which this un is designed, upon slight heating (w ile standing in the sun and the like) tend to build up a pressure in closed. chambers due to their high vapor tension. This action forces liquid out of vent holes when the chambers are full. In the present device expansion within the container 7 merely causes the head of liquid in pipe to rise into the chamber 27. The chamber receive the over= liow forced out of container 7 and none is spilled. When the gun is put into operation the pressure is almost immediately relieved and the head of liquid in chamber 27 .cases where the liquid expands greatly upon heating, so much so in fact, that an inordinately long pipe 27 would otherwise he needed to take care of the overflow.v The bottom of the chamber 3l may be tapered, if desired as shown in Fig. ll, whereby liquid positively drains back to the pipe 25. The form of pipe shown in Figs. l3 and 14 has the advantage of acting as a pocket or trap at its top, when the gun is tilted over, thereby preventing residue material on the walls of" the chamber 31 from escaping. This trap action may be enhanced by :t'orming the top according to the upper lines shown in Fig. 1d. 'The. Fig. 13 modification is the easiest to make, while the Fig. 14 modification is the most positively efi'ective.

The gun assembly 1 will now be considered. As stated, the nipple 5 holds it to the reservoir assembly 3. It comprises a body 33 provided with an upwardly extending lug 35 having a hole 37 therein for hanging the device on a hook or the like. The lug 35 serves other purposes to be described.

The body 33 is provided with a longitudinal material passage 39 and a similar passage 4:1 for air. The passage 41 is jogged 45. The u per end of the liner is tap. red to fit the sai taper of the passage 43 thereby sealing the passage 41 from the passage 39.

It is counter grooved circumferentially at 47 by means of which the front and rear portions of passage 41 are connected and made continuous. It is rovided with threads, a shoulder and a gas et at its lower end for sealing it to the body as the said tapered portions seat. It carries, at its lower; end a threaded extension 49 for cooperation with said nip le 5. The liner 45 serves to pass material rom the pipe 23 to the passa e 39. The construction employed saves Weig t in the gun.

The passage 41 is counter-bored at a point 51 rearward thereof .where it is provided I with a branc passage 53. The passage 53 receives a downwardly extending pipe 55,

' shouldered at 57 whereby a fibre or other hand grip 59 is held to the body 33. A guard 61 on the body 33 prevents an operators hand from slipping from the grip 59. The lower end of the pipe 55. is threaded to receive a flexible compressed air line (not shown).

The counter-bore 51 is provided with a threaded packing gland 63' through which passes a valve stem 65. 'The stem 65 is packed against leakage in the gland 63 by a packing nut 67, operative on proper packing about the stem in the gland.

At its inner end the stem 65 is provided with a tapered valve head .69 adapted to seat on a beveled portion of the counter-bore 51. The head 69 is held to its seat by a sprin 71 reacting between the head and the sai gland 63. Air pressure from the pipe 55 normally aids this seating.

The outer end of the stem 65 is threaded 'with a cylindrical shouldered nut 73 which overhangs the stem and is locked thereto by a lock bolt 75 reacting between the nut 73 and the threaded end of said stem.

The stem 65 is made operative by means of a saddle strap 77 (Figs. 9 to 11), pivoted to the two legs 79 of a split trigger 81 (Fig. 1). The le s 79 are pivoted to said In 35. The strap 7 reaches around the rear 0 the n and is formed at its rear end with a saddle 83 (Fig. 12). This saddle 83 is provided with a hole 85 adapted to receive slidably the cylindrical portion of said nut 73 (Fig. 9) but not its shoulder. An opening 87 leads to the hole 85 from the lower edge of the saddle 83 and is large enough to admit the stem 65, but not said cylindrical portion.

Hence the valve stem 65 may be made 0perative and the air valve opened by means of the saddle piece 83 operating on the shoulder of nut 73 by pulling the trigger 81.

The nut 73 is adjusted so that the said shoulder is just against the saddle piece when the trigger is in its forward position. If it is desired to make the trigger inoperative on the air valve, the stem 65 may be pulled rearwardly by hand (Fig. 10), until the stem cooperates with the opening 87, whereupon the saddle strap may be raised (Fig. 11) and the trig er 81 may be pulled rearwardly without a ecting the air valve.

7 The forward end of the paint passage 39 has threaded therein a nipple 89. This nipple 89 is bored to communicate with said passage 39 and on its forward end is provided with a bored teat 91 (Fig. 3). The surface connections between the difierential outside and inside diameters of the nipple and teat are conical. A tapered valve head 93 fits the inner cone and a ram 95, slightly longer than the bore in the teat, slidably fits said bore. A rearwardly extending valve stem 97 passes through the bore of the nipple 89 and the passage 39. lit is adapted to permit passage of liquid between it and both bores which it asses through. A ported guide 99 aligns t e head 93 and permits passage of liquid.

The stem 97 passes out of the passage 39 rearwardly through a packing gland 101 and a packing nut 103 therefor, with the usual .1

packing. A spring 105 wound to the stem 97 in a slot reacts between -said stem and the gland 101 to normally hold the head 93 seated, thereby cutting ofi flow of material I 81 rearwardly, the air valve is immediately opened while play exists between the humps 111- and the shoulder of nut 107, (Fig. 9).

whereb the material valve opens slightly later. eversal of action causes the material valve to close before the air valve closes. As will be shown the air operates aspiratively on the material and hence it is desirable to have aspirating air available for immediately taking care of the material when the material valve is opened, and likewise desirable to have such air after the material valve is shut so that any chance drips due to closing of said valve will be atomized rather than be dropped on completed paint work. a

The nozzle of the gun will now be considered (Figs. 1 to 5). The forward portion of the body 33 is formed as a cylinder 113. This cylinder 113 is faced flat at its front end except where the nipple 89 seats on a bevel. It is threaded rearwardly to receive a ring 115 (Fig. 2) to which ring is soldered, brazed or otherwise permanently formed a ip 117 which is flanged to rotatably hold the flange of a cylinder or jacket 119. To all intents and purposes the rings 115 and 117 are one piece, their function being to draw the jacket rearwardly der, 180 degrees apart, lead from said face forwardly in jacket 113 and conver e at their forward ends. They enter at sai forward ends, a crater-like depression 125 formed in the jacket 119. The bottom of said crater depression 125 is bored toreceive in force fit a bushing 127 The bushin is bored as well as is the jacket 119 in suc manner as to passably clear cylindrical portions of the nipple 89 and the teat 91 at all oints including the conical connecting sur aces. The nipple is formed .to receive a wrench for tightening at a shoulder 90. The nipple 89 is provided at its forward extension with spaced ribs or fins 129 of such height that they slidably but accurately fit the larger bore of the bushing 127. From the foregoing it is evident that when the face of shoulder 121 of the jacket 119 seats on the facing of the cylinder 113 that there is a passage at all points between the portions of the nipple 89 and the various bores within the shoulder and bushing 127 The grip 117 may be loosened and tightened at will to permit moving the said auxilia passages 123 from a vertical position wit respect to one another (Figs. 2 to 4) to a horizontal position (Figs. 1 and 5).

The said air passage 41 passes forwardl through cylinder 113 "at the bottom thereo and emerges at the face thereof in such a shape and manner that its exit ,hole 131 will feed the said passage around the' nipple 89,

and either of the auxiliary passages 123 should they be downwardly positioned.

Furthermore, at 90 degree nitervals about said face auxiliary feed holes or pits 133 are formed. These holes 133 are connected with the exit hole 131 by sideward sub-bores 135 whereby they also receive air from the passage 41. They however do not feed the passage around the nipple 89 but only the auxiliary passages 123 when said passages are properly positioned.

With this structure in mind the following conclusions hold:

Air coming from passage 41, when the air valve is open will be available at any of the four holes 133 and in the passage around the nipple 89. It may always pass through the passage about the nipple 89, regardless of the position of jacket 119. If the jacket is in any position, not vertical or horizontal air can not pass from any hole 131, or 133 to the auxiliary passages 123.

Then the jacket is positioned with the passages 123 vertically arranged, hole 131 and t e upper hole 133 feed the auxiliary passages 123. Hole 131 further feeds air to the passage about nipple 89 and if the material valve be open such air will aspirate material to a spray. The air passing through the vertically arranged auxiliary passages is rojected on this spray, flattening in to a an shape horizontally arranged. When the jacket is positioned with the passages 123 horizontally arranged, the side- Ward holes 133 feed the auxiliary passages While the hole 131 feeds only the passage around the nipple 89. Hence if the device is aspirating1 as before described, the air leaving the orizontally arran ed passages 123.w1ll flatten the spray vertically and a vertical fan shaped spra is attained.

Hence either a vertica or a horizontal fan shaped spray may be had, or the passages 123 may be set out of line with any of the holes 131, or 133, and a circular spray had.

If the air valve is disconnected as hereinbefore described, raw material may be ejected from the teat 91, that is, if paint is being fed to the gun by pressure.

1 Complete operation of the gun is as folows:

The lower lid 11 is removed, the container 7 is inverted and material poured therein.

Thelid is applied and fastened and the device turned upright. A compressed air line is fastened to the pipe 55.

If the device happens to stand in a heated place before it is actually used after having pair of horizontally arranged holes 133- (Fig. 5). This by-passage of air flattens the spray, said spray starting when the trigger 81 is further pulled back far enough to open the material valve, the play at the nut 107 having been taken up by the first rearward movement of the trigger. When the material valve opens the ram 95 leaves its passage in the teat 91 entirely. Paint is sucked out by air which leaves the annular port around the teat.

To turn off the spray the trigger is released. Immediately the ram. 95 enters its hole forcing material out. The air valve closes after the ram and material valve have come to rest at seat. Hence as irating air sends into spray all material orced from the passage of teat 91 by the ram 95.

To throw a horizontal fan shaped spray it is only necessary to loosen the grip 117, set the passages 123 vertical and re-tighten the grip. Hence air is by-passed from the hole 131 and the upper hole 133, as described (see Fig. 4) and a horizontalfan shape is obtained. I

From the above it will be seen that the several objects of the invention are attained and other advanta eous results achieved.

'As many modifications of the embodiments above illustrated might be made without departing from the spirit or scope of the present invention, it is intended that the above description and accompanying drawings and claims shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A material reservoir for ainting equipment comprising a closed c amber, means for taking material from the chamber, a vent for the chamber comprising a tube open at each end reaching from the inside bottom of the chamber, to a point-above the top of the chamber and an enlarged chamber in the line of said tube above the top of the chamber adapted to receive upwardly pressed material from the chamber below, the bottom of said enlarged chamber being funnel shaped at the bottom thereof so as to easily return material to the lower chamber and the top thereof cone shaped down- Wardly toward the vent pipe, whereby residue material is trapped when the container is inverted.

2. A non-drip paint spraying device comprising in combination a material reservoir and an aspirating device therefor, said reservoir being a closed chamber having a vent comprising a tube open at each end reaching from the inside bottom of the chamber to a point above the top thereof, an enlarged trap chamber in the line of said tube above the top of the said first chamber adapted when the aspirating device is inoperable to receive upwardly expanding material from the chamber below and when the aspirating device is operable to feed air from the upper open end of said tube to the reservoir which is then under reduced pressure.

3. A spray head for paint guns comprising a faced cylinder, a jacket thereover, a face shoulder within the jacket adapted to cooperate with said first face, a material nipple screwed centrally to said first face, said jacket being provided with a central hole arran ed in spaced relationship to the nipple an ribs on the nipple, said jacket being longitudinally and rotatably movable on said nipple, said first face having a first port therein leading air thereto, and other ports therein communicating with said first port, said other ports being spaced at intervals and opposite one another in pairs, and said jacket being also provided with a pair of auxiliary ports passing to the acket face and adapted to align with various pairs of said other ports in said first face when said jacket is rotated, said first-named port feeding air to the other ports and to the space about the nipple, whereby material is aspirated in a spray from the nippieand said spray deformed to a fan shape by air from said auxiliary ports.

4. A spray head forpaint guns comprising a faced cylinder, a packet thereover, a face shoulder within the jacket adapted to cooperate with said first face, a material nipple screwed centrall to said first face, said jacket being provlded with a central hole arranged in spaced relationship to the nipple and ribs on the nipple, said jacket being longitudinally and rotatably movable on said nlpple, said first face having a first port therein leading air thereto, and other ports therein communicating with said first port, said other ports being spaced at intervals and opposite one another in pairs, and said jacket being also provided with a pair of auxiliary ports passing to the jacket face and adapted to align with various pairs of said other ports in said first face when said jacket is rotated, saidfirst-named port feed- 1n ab%ut the nipple whereby material may be aspirated in'a spray from the nipple and air to the other ports and to the space said spray deformed to a fan shape by air from said auxiliary ports and means for clamping said jacket face to the cylinder face in a position of alignment of auxiliary passages with any pair of spaced holes or with no such alignment, whereby a round spray is had.

5. A body construction for a paint gun having a material and an air passage, comprising a body piece having a material passage, a spaced air passage, a passage joining the twosaid passages laterally and leading to the outside of said body, a bored liner having a roove therein, said liner tightly fitting sai except at the point of intersection of 'said groove with said air passage whereby said air passage is made continuous and separated from the material passage.

6. A spray head for paint guns comprising a cylinder having a passage therein for leading air to the face of said cylinder, a rotatable jacket cooperating with said cylinder at said face, said cylinder having holes therein spaced in pairs, said holes cooperating with said passage and said cylinder, a material nipple, said jacket being provided last-named passage at all points with a central opening adapted to receive said nipple and centrally space said nipple with respect to said holes, said opening receiving air from said first-named hole, said jacket being further provided with two passages adapted to receive air from any of the .pairs of holes if so desired, and to direct said air on that air leaving the central opening about the nipple.

In testimony whereof, I have signed my name to this specification, this 30th day of July, 1925.

THEODORE BIRKENMAIER. 

